Dumbells - where / what to get

Got a quick question- I just moved out of a sublet where I had dumbbells, and now I'm on my own. No weights!

What are the best kind of dumbbells? I am curling 25 lbs per arm right now, and would like to work up to 40. I'm thinking to get the kind of dumbells with a bunch of plates that slide on a bar and then get spring-clipped on.